Study on mice revealed how antioxidants may increase cancer cells

A study published in the Journal Nature by medical investigator, Sean J. Morrison and co-workers at the Children’s Medical Center Research Institute – in the University of Texas Medical Center – showed how antioxidants may have a negative impact in cancer cells and may contribute to its growth.

Morrison and his team examined cancer progression in mice transplanted with skin cancer cells (NSG), better known as melanoma. NSG mice are immunodeficient mice, which are used to model human diseases.

Antioxidant are nutrients and enzymes in our blood that make the free radicals harmless by disarming them. They work by giving one of their electrons to “neutralize” these free radicals. Hence,they prevent the chemical reaction known as oxidation. Credit: Dynamic Nutrition

First, they divided the mice into two groups. Second, to the first group they gave doses of N-acetylcysteine (NAC) – a common antioxidant used in nutritional and bodybuilding supplements, in some important medical treatments such as HIV/ AIDS patients and in some children with genetic disorders. To the other group nothing was given. Finally, the results showed that mice that were given NAC suffered from higher levels of cancer in the blood and tumors grew large.

Moreover, the results revealed that there can be bad cells from cancer that appear to benefit more from antioxidants than normal cells. What happens is that as melanoma cells break off from the primary tumor and spread- a process known as metastasis- they are more vulnerable.

“We discovered that metastasizing melanoma cells experience very high levels of oxidative stress, which leads to the death of most metastasizing cells […] The idea that antioxidants are good for you has been so strong that there have been clinical trials done in which cancer patients were administered antioxidants,” said corresponding author and Howard Hughes Medical Institute Investigator, Sean J. Morrison in the study.

Before this study, it was known that eating antioxidants in fruits and vegetables was helpful to stop cancer’s growth, however, this new research called that theory into question. The study explained that antioxidants don’t cause cancer, but they may increase the development of its cells causing an advance growth process that could affect patients carrying the disease.

What really happens with antioxidants and cancer’s cells?

When antioxidant supplements are given, the possibility exists that they may give life to cancerous cells that are almost dead. Also, it’s not yet proven if antioxidants can actually prevent cancer before it starts.

What is proven is that they prevent cells damage, especially DNA, and this decreases the possibility of a cell going out of control, which is what happens when someone has cancer. Experts predict that around 1.65 million people will be diagnosed with cancer this year, and approximately 600,000 will die as the result of the disease.

Finally, Morrison emphasized how antioxidants in fruits and vegetables could be critical to reducing cancer’s rates and how melanoma cells are more sensitive to stress. Moreover, it is possible that cancer patients would benefit from pro-oxidants.

“Our data suggest the reason for this: cancer cells benefit more from antioxidants than normal cells do […] This finding also opens up the possibility that when treating cancer, we should test whether increasing oxidative stress through the use of pro-oxidants would prevent metastasis […]One potential approach is to target the folate pathway that melanoma cells use to survive oxidative stress, which would increase the level of oxidative stress in the cancer cells.” Said Morrison in a statement.